package com.ulwx.tool.path;

import com.ulwx.tool.CollectionUtils;

import java.util.*;

abstract class PStringUtils {

   private static final String[] EMPTY_STRING_ARRAY = {};

   private static final String FOLDER_SEPARATOR = "/";

   private static final String WINDOWS_FOLDER_SEPARATOR = "\\";

   private static final String TOP_PATH = "..";

   private static final String CURRENT_PATH = ".";

   private static final char EXTENSION_SEPARATOR = '.';


   //---------------------------------------------------------------------
   // General convenience methods for working with Strings
   //---------------------------------------------------------------------

   /**
    * Check whether the given object (possibly a {@code String}) is empty.
    * This is effectively a shortcut for {@code !hasLength(String)}.
    * <p>This method accepts any Object as an argument, comparing it to
    * {@code null} and the empty String. As a consequence, this method
    * will never return {@code true} for a non-null non-String object.
    * <p>The Object signature is useful for general attribute handling code
    * that commonly deals with Strings but generally has to iterate over
    * Objects since attributes may e.g. be primitive value objects as well.
    * <p><b>Note: If the object is typed to {@code String} upfront, prefer
    * {@link #hasLength(String)} or {@link #hasText(String)} instead.</b>
    * @param str the candidate object (possibly a {@code String})
    * @since 3.2.1
    * @deprecated as of 5.3, in favor of {@link #hasLength(String)} and
    * {@link #hasText(String)} (or {@link PObjectUtils#isEmpty(Object)})
    */
   @Deprecated
   public static boolean isEmpty( Object str) {
       return (str == null || "".equals(str));
   }

   /**
    * Check that the given {@code CharSequence} is neither {@code null} nor
    * of length 0.
    * <p>Note: this method returns {@code true} for a {@code CharSequence}
    * that purely consists of whitespace.
    * <p><pre class="code">
    * StringUtils.hasLength(null) = false
    * StringUtils.hasLength("") = false
    * StringUtils.hasLength(" ") = true
    * StringUtils.hasLength("Hello") = true
    * </pre>
    * @param str the {@code CharSequence} to check (may be {@code null})
    * @return {@code true} if the {@code CharSequence} is not {@code null} and has length
    * @see #hasLength(String)
    * @see #hasText(CharSequence)
    */
   public static boolean hasLength( CharSequence str) {
       return (str != null && str.length() > 0);
   }

   /**
    * Check that the given {@code String} is neither {@code null} nor of length 0.
    * <p>Note: this method returns {@code true} for a {@code String} that
    * purely consists of whitespace.
    * @param str the {@code String} to check (may be {@code null})
    * @return {@code true} if the {@code String} is not {@code null} and has length
    * @see #hasLength(CharSequence)
    * @see #hasText(String)
    */
   public static boolean hasLength( String str) {
       return (str != null && !str.isEmpty());
   }

   /**
    * Check whether the given {@code CharSequence} contains actual <em>text</em>.
    * <p>More specifically, this method returns {@code true} if the
    * {@code CharSequence} is not {@code null}, its length is greater than
    * 0, and it contains at least one non-whitespace character.
    * <p><pre class="code">
    * StringUtils.hasText(null) = false
    * StringUtils.hasText("") = false
    * StringUtils.hasText(" ") = false
    * StringUtils.hasText("12345") = true
    * StringUtils.hasText(" 12345 ") = true
    * </pre>
    * @param str the {@code CharSequence} to check (may be {@code null})
    * @return {@code true} if the {@code CharSequence} is not {@code null},
    * its length is greater than 0, and it does not contain whitespace only
    * @see #hasText(String)
    * @see #hasLength(CharSequence)
    * @see Character#isWhitespace
    */
   public static boolean hasText( CharSequence str) {
       return (str != null && str.length() > 0 && containsText(str));
   }

   /**
    * Check whether the given {@code String} contains actual <em>text</em>.
    * <p>More specifically, this method returns {@code true} if the
    * {@code String} is not {@code null}, its length is greater than 0,
    * and it contains at least one non-whitespace character.
    * @param str the {@code String} to check (may be {@code null})
    * @return {@code true} if the {@code String} is not {@code null}, its
    * length is greater than 0, and it does not contain whitespace only
    * @see #hasText(CharSequence)
    * @see #hasLength(String)
    * @see Character#isWhitespace
    */
   public static boolean hasText( String str) {
       return (str != null && !str.isEmpty() && containsText(str));
   }

   private static boolean containsText(CharSequence str) {
       int strLen = str.length();
       for (int i = 0; i < strLen; i++) {
           if (!Character.isWhitespace(str.charAt(i))) {
               return true;
           }
       }
       return false;
   }

   /**
    * Check whether the given {@code CharSequence} contains any whitespace characters.
    * @param str the {@code CharSequence} to check (may be {@code null})
    * @return {@code true} if the {@code CharSequence} is not empty and
    * contains at least 1 whitespace character
    * @see Character#isWhitespace
    */
   public static boolean containsWhitespace( CharSequence str) {
       if (!hasLength(str)) {
           return false;
       }

       int strLen = str.length();
       for (int i = 0; i < strLen; i++) {
           if (Character.isWhitespace(str.charAt(i))) {
               return true;
           }
       }
       return false;
   }

   /**
    * Check whether the given {@code String} contains any whitespace characters.
    * @param str the {@code String} to check (may be {@code null})
    * @return {@code true} if the {@code String} is not empty and
    * contains at least 1 whitespace character
    * @see #containsWhitespace(CharSequence)
    */
   public static boolean containsWhitespace( String str) {
       return containsWhitespace((CharSequence) str);
   }

   /**
    * Trim leading and trailing whitespace from the given {@code String}.
    * @param str the {@code String} to check
    * @return the trimmed {@code String}
    * @see Character#isWhitespace
    */
   public static String trimWhitespace(String str) {
       if (!hasLength(str)) {
           return str;
       }

       int beginIndex = 0;
       int endIndex = str.length() - 1;

       while (beginIndex <= endIndex && Character.isWhitespace(str.charAt(beginIndex))) {
           beginIndex++;
       }

       while (endIndex > beginIndex && Character.isWhitespace(str.charAt(endIndex))) {
           endIndex--;
       }

       return str.substring(beginIndex, endIndex + 1);
   }

   /**
    * Trim <i>all</i> whitespace from the given {@code String}:
    * leading, trailing, and in between characters.
    * @param str the {@code String} to check
    * @return the trimmed {@code String}
    * @see Character#isWhitespace
    */
   public static String trimAllWhitespace(String str) {
       if (!hasLength(str)) {
           return str;
       }

       int len = str.length();
       StringBuilder sb = new StringBuilder(str.length());
       for (int i = 0; i < len; i++) {
           char c = str.charAt(i);
           if (!Character.isWhitespace(c)) {
               sb.append(c);
           }
       }
       return sb.toString();
   }

   /**
    * Trim leading whitespace from the given {@code String}.
    * @param str the {@code String} to check
    * @return the trimmed {@code String}
    * @see Character#isWhitespace
    */
   public static String trimLeadingWhitespace(String str) {
       if (!hasLength(str)) {
           return str;
       }

       int beginIdx = 0;
       while (beginIdx < str.length() && Character.isWhitespace(str.charAt(beginIdx))) {
           beginIdx++;
       }
       return str.substring(beginIdx);
   }

   /**
    * Trim trailing whitespace from the given {@code String}.
    * @param str the {@code String} to check
    * @return the trimmed {@code String}
    * @see Character#isWhitespace
    */
   public static String trimTrailingWhitespace(String str) {
       if (!hasLength(str)) {
           return str;
       }

       int endIdx = str.length() - 1;
       while (endIdx >= 0 && Character.isWhitespace(str.charAt(endIdx))) {
           endIdx--;
       }
       return str.substring(0, endIdx + 1);
   }

   /**
    * Trim all occurrences of the supplied leading character from the given {@code String}.
    * @param str the {@code String} to check
    * @param leadingCharacter the leading character to be trimmed
    * @return the trimmed {@code String}
    */
   public static String trimLeadingCharacter(String str, char leadingCharacter) {
       if (!hasLength(str)) {
           return str;
       }

       int beginIdx = 0;
       while (beginIdx < str.length() && leadingCharacter == str.charAt(beginIdx)) {
           beginIdx++;
       }
       return str.substring(beginIdx);
   }

   /**
    * Trim all occurrences of the supplied trailing character from the given {@code String}.
    * @param str the {@code String} to check
    * @param trailingCharacter the trailing character to be trimmed
    * @return the trimmed {@code String}
    */
   public static String trimTrailingCharacter(String str, char trailingCharacter) {
       if (!hasLength(str)) {
           return str;
       }

       int endIdx = str.length() - 1;
       while (endIdx >= 0 && trailingCharacter == str.charAt(endIdx)) {
           endIdx--;
       }
       return str.substring(0, endIdx + 1);
   }

   /**
    * Test if the given {@code String} matches the given single character.
    * @param str the {@code String} to check
    * @param singleCharacter the character to compare to
    * @since 5.2.9
    */
   public static boolean matchesCharacter( String str, char singleCharacter) {
       return (str != null && str.length() == 1 && str.charAt(0) == singleCharacter);
   }

   /**
    * Test if the given {@code String} starts with the specified prefix,
    * ignoring upper/lower case.
    * @param str the {@code String} to check
    * @param prefix the prefix to look for
    * @see String#startsWith
    */
   public static boolean startsWithIgnoreCase( String str,  String prefix) {
       return (str != null && prefix != null && str.length() >= prefix.length() &&
               str.regionMatches(true, 0, prefix, 0, prefix.length()));
   }

   /**
    * Test if the given {@code String} ends with the specified suffix,
    * ignoring upper/lower case.
    * @param str the {@code String} to check
    * @param suffix the suffix to look for
    * @see String#endsWith
    */
   public static boolean endsWithIgnoreCase( String str,  String suffix) {
       return (str != null && suffix != null && str.length() >= suffix.length() &&
               str.regionMatches(true, str.length() - suffix.length(), suffix, 0, suffix.length()));
   }

   /**
    * Test whether the given string matches the given substring
    * at the given index.
    * @param str the original string (or StringBuilder)
    * @param index the index in the original string to start matching against
    * @param substring the substring to match at the given index
    */
   public static boolean substringMatch(CharSequence str, int index, CharSequence substring) {
       if (index + substring.length() > str.length()) {
           return false;
       }
       for (int i = 0; i < substring.length(); i++) {
           if (str.charAt(index + i) != substring.charAt(i)) {
               return false;
           }
       }
       return true;
   }

   /**
    * Count the occurrences of the substring {@code sub} in string {@code str}.
    * @param str string to search in
    * @param sub string to search for
    */
   public static int countOccurrencesOf(String str, String sub) {
       if (!hasLength(str) || !hasLength(sub)) {
           return 0;
       }

       int count = 0;
       int pos = 0;
       int idx;
       while ((idx = str.indexOf(sub, pos)) != -1) {
           ++count;
           pos = idx + sub.length();
       }
       return count;
   }

   /**
    * Replace all occurrences of a substring within a string with another string.
    * @param inString {@code String} to examine
    * @param oldPattern {@code String} to replace
    * @param newPattern {@code String} to insert
    * @return a {@code String} with the replacements
    */
   public static String replace(String inString, String oldPattern,  String newPattern) {
       if (!hasLength(inString) || !hasLength(oldPattern) || newPattern == null) {
           return inString;
       }
       int index = inString.indexOf(oldPattern);
       if (index == -1) {
           // no occurrence -> can return input as-is
           return inString;
       }

       int capacity = inString.length();
       if (newPattern.length() > oldPattern.length()) {
           capacity += 16;
       }
       StringBuilder sb = new StringBuilder(capacity);

       int pos = 0;  // our position in the old string
       int patLen = oldPattern.length();
       while (index >= 0) {
           sb.append(inString, pos, index);
           sb.append(newPattern);
           pos = index + patLen;
           index = inString.indexOf(oldPattern, pos);
       }

       // append any characters to the right of a match
       sb.append(inString, pos, inString.length());
       return sb.toString();
   }

   /**
    * Delete all occurrences of the given substring.
    * @param inString the original {@code String}
    * @param pattern the pattern to delete all occurrences of
    * @return the resulting {@code String}
    */
   public static String delete(String inString, String pattern) {
       return replace(inString, pattern, "");
   }

   /**
    * Delete any character in a given {@code String}.
    * @param inString the original {@code String}
    * @param charsToDelete a set of characters to delete.
    * E.g. "az\n" will delete 'a's, 'z's and new lines.
    * @return the resulting {@code String}
    */
   public static String deleteAny(String inString,  String charsToDelete) {
       if (!hasLength(inString) || !hasLength(charsToDelete)) {
           return inString;
       }

       int lastCharIndex = 0;
       char[] result = new char[inString.length()];
       for (int i = 0; i < inString.length(); i++) {
           char c = inString.charAt(i);
           if (charsToDelete.indexOf(c) == -1) {
               result[lastCharIndex++] = c;
           }
       }
       if (lastCharIndex == inString.length()) {
           return inString;
       }
       return new String(result, 0, lastCharIndex);
   }

   //---------------------------------------------------------------------
   // Convenience methods for working with formatted Strings
   //---------------------------------------------------------------------

   /**
    * Quote the given {@code String} with single quotes.
    * @param str the input {@code String} (e.g. "myString")
    * @return the quoted {@code String} (e.g. "'myString'"),
    * or {@code null} if the input was {@code null}
    */

   public static String quote( String str) {
       return (str != null ? "'" + str + "'" : null);
   }

   /**
    * Turn the given Object into a {@code String} with single quotes
    * if it is a {@code String}; keeping the Object as-is else.
    * @param obj the input Object (e.g. "myString")
    * @return the quoted {@code String} (e.g. "'myString'"),
    * or the input object as-is if not a {@code String}
    */

   public static Object quoteIfString( Object obj) {
       return (obj instanceof String ? quote((String) obj) : obj);
   }

   /**
    * Unqualify a string qualified by a '.' dot character. For example,
    * "this.name.is.qualified", returns "qualified".
    * @param qualifiedName the qualified name
    */
   public static String unqualify(String qualifiedName) {
       return unqualify(qualifiedName, '.');
   }

   /**
    * Unqualify a string qualified by a separator character. For example,
    * "this:name:is:qualified" returns "qualified" if using a ':' separator.
    * @param qualifiedName the qualified name
    * @param separator the separator
    */
   public static String unqualify(String qualifiedName, char separator) {
       return qualifiedName.substring(qualifiedName.lastIndexOf(separator) + 1);
   }

   /**
    * Capitalize a {@code String}, changing the first letter to
    * upper case as per {@link Character#toUpperCase(char)}.
    * No other letters are changed.
    * @param str the {@code String} to capitalize
    * @return the capitalized {@code String}
    */
   public static String capitalize(String str) {
       return changeFirstCharacterCase(str, true);
   }

   /**
    * Uncapitalize a {@code String}, changing the first letter to
    * lower case as per {@link Character#toLowerCase(char)}.
    * No other letters are changed.
    * @param str the {@code String} to uncapitalize
    * @return the uncapitalized {@code String}
    */
   public static String uncapitalize(String str) {
       return changeFirstCharacterCase(str, false);
   }

   private static String changeFirstCharacterCase(String str, boolean capitalize) {
       if (!hasLength(str)) {
           return str;
       }

       char baseChar = str.charAt(0);
       char updatedChar;
       if (capitalize) {
           updatedChar = Character.toUpperCase(baseChar);
       }
       else {
           updatedChar = Character.toLowerCase(baseChar);
       }
       if (baseChar == updatedChar) {
           return str;
       }

       char[] chars = str.toCharArray();
       chars[0] = updatedChar;
       return new String(chars, 0, chars.length);
   }

   /**
    * Extract the filename from the given Java resource path,
    * e.g. {@code "mypath/myfile.txt" -> "myfile.txt"}.
    * @param path the file path (may be {@code null})
    * @return the extracted filename, or {@code null} if none
    */

   public static String getFilename( String path) {
       if (path == null) {
           return null;
       }

       int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
       return (separatorIndex != -1 ? path.substring(separatorIndex + 1) : path);
   }

   /**
    * Extract the filename extension from the given Java resource path,
    * e.g. "mypath/myfile.txt" -> "txt".
    * @param path the file path (may be {@code null})
    * @return the extracted filename extension, or {@code null} if none
    */

   public static String getFilenameExtension( String path) {
       if (path == null) {
           return null;
       }

       int extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
       if (extIndex == -1) {
           return null;
       }

       int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
       if (folderIndex > extIndex) {
           return null;
       }

       return path.substring(extIndex + 1);
   }

   /**
    * Strip the filename extension from the given Java resource path,
    * e.g. "mypath/myfile.txt" -> "mypath/myfile".
    * @param path the file path
    * @return the path with stripped filename extension
    */
   public static String stripFilenameExtension(String path) {
       int extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
       if (extIndex == -1) {
           return path;
       }

       int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
       if (folderIndex > extIndex) {
           return path;
       }

       return path.substring(0, extIndex);
   }

   /**
    * Apply the given relative path to the given Java resource path,
    * assuming standard Java folder separation (i.e. "/" separators).
    * @param path the path to start from (usually a full file path)
    * @param relativePath the relative path to apply
    * (relative to the full file path above)
    * @return the full file path that results from applying the relative path
    */
   public static String applyRelativePath(String path, String relativePath) {
       int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
       if (separatorIndex != -1) {
           String newPath = path.substring(0, separatorIndex);
           if (!relativePath.startsWith(FOLDER_SEPARATOR)) {
               newPath += FOLDER_SEPARATOR;
           }
           return newPath + relativePath;
       }
       else {
           return relativePath;
       }
   }

   /**
    * Normalize the path by suppressing sequences like "path/.." and
    * inner simple dots.
    * <p>The result is convenient for path comparison. For other uses,
    * notice that Windows separators ("\") are replaced by simple slashes.
    * <p><strong>NOTE</strong> that {@code cleanPath} should not be depended
    * upon in a security context. Other mechanisms should be used to prevent
    * path-traversal issues.
    * @param path the original path
    * @return the normalized path
    */
   public static String cleanPath(String path) {
       if (!hasLength(path)) {
           return path;
       }
       String pathToUse = replace(path, WINDOWS_FOLDER_SEPARATOR, FOLDER_SEPARATOR);

       // Shortcut if there is no work to do
       if (pathToUse.indexOf('.') == -1) {
           return pathToUse;
       }

       // Strip prefix from path to analyze, to not treat it as part of the
       // first path element. This is necessary to correctly parse paths like
       // "file:core/../core/io/Resource.class", where the ".." should just
       // strip the first "core" directory while keeping the "file:" prefix.
       int prefixIndex = pathToUse.indexOf(':');
       String prefix = "";
       if (prefixIndex != -1) {
           prefix = pathToUse.substring(0, prefixIndex + 1);
           if (prefix.contains(FOLDER_SEPARATOR)) {
               prefix = "";
           }
           else {
               pathToUse = pathToUse.substring(prefixIndex + 1);
           }
       }
       if (pathToUse.startsWith(FOLDER_SEPARATOR)) {
           prefix = prefix + FOLDER_SEPARATOR;
           pathToUse = pathToUse.substring(1);
       }

       String[] pathArray = delimitedListToStringArray(pathToUse, FOLDER_SEPARATOR);
       Deque<String> pathElements = new ArrayDeque<>();
       int tops = 0;

       for (int i = pathArray.length - 1; i >= 0; i--) {
           String element = pathArray[i];
           if (CURRENT_PATH.equals(element)) {
               // Points to current directory - drop it.
           }
           else if (TOP_PATH.equals(element)) {
               // Registering top path found.
               tops++;
           }
           else {
               if (tops > 0) {
                   // Merging path element with element corresponding to top path.
                   tops--;
               }
               else {
                   // Normal path element found.
                   pathElements.addFirst(element);
               }
           }
       }

       // All path elements stayed the same - shortcut
       if (pathArray.length == pathElements.size()) {
           return prefix + pathToUse;
       }
       // Remaining top paths need to be retained.
       for (int i = 0; i < tops; i++) {
           pathElements.addFirst(TOP_PATH);
       }
       // If nothing else left, at least explicitly point to current path.
       if (pathElements.size() == 1 && pathElements.getLast().isEmpty() && !prefix.endsWith(FOLDER_SEPARATOR)) {
           pathElements.addFirst(CURRENT_PATH);
       }

       return prefix + collectionToDelimitedString(pathElements, FOLDER_SEPARATOR);
   }

   /**
    * Compare two paths after normalization of them.
    * @param path1 first path for comparison
    * @param path2 second path for comparison
    * @return whether the two paths are equivalent after normalization
    */
   public static boolean pathEquals(String path1, String path2) {
       return cleanPath(path1).equals(cleanPath(path2));
   }



   /**
    * Parse the given {@code String} value into a {@link Locale}, accepting
    * the {@link Locale#toString} format as well as BCP 47 language tags.
    * @param localeValue the locale value: following either {@code Locale's}
    * {@code toString()} format ("en", "en_UK", etc), also accepting spaces as
    * separators (as an alternative to underscores), or BCP 47 (e.g. "en-UK")
    * as specified by {@link Locale#forLanguageTag} on Java 7+
    * @return a corresponding {@code Locale} instance, or {@code null} if none
    * @throws IllegalArgumentException in case of an invalid locale specification
    * @since 5.0.4
    * @see #parseLocaleString
    * @see Locale#forLanguageTag
    */

   public static Locale parseLocale(String localeValue) {
       String[] tokens = tokenizeLocaleSource(localeValue);
       if (tokens.length == 1) {
           validateLocalePart(localeValue);
           Locale resolved = Locale.forLanguageTag(localeValue);
           if (resolved.getLanguage().length() > 0) {
               return resolved;
           }
       }
       return parseLocaleTokens(localeValue, tokens);
   }

   /**
    * Parse the given {@code String} representation into a {@link Locale}.
    * <p>For many parsing scenarios, this is an inverse operation of
    * {@link Locale#toString Locale's toString}, in a lenient sense.
    * This method does not aim for strict {@code Locale} design compliance;
    * it is rather specifically tailored for typical Spring parsing needs.
    * <p><b>Note: This delegate does not accept the BCP 47 language tag format.
    * Please use {@link #parseLocale} for lenient parsing of both formats.</b>
    * @param localeString the locale {@code String}: following {@code Locale's}
    * {@code toString()} format ("en", "en_UK", etc), also accepting spaces as
    * separators (as an alternative to underscores)
    * @return a corresponding {@code Locale} instance, or {@code null} if none
    * @throws IllegalArgumentException in case of an invalid locale specification
    */

   public static Locale parseLocaleString(String localeString) {
       return parseLocaleTokens(localeString, tokenizeLocaleSource(localeString));
   }

   private static String[] tokenizeLocaleSource(String localeSource) {
       return tokenizeToStringArray(localeSource, "_ ", false, false);
   }


   private static Locale parseLocaleTokens(String localeString, String[] tokens) {
       String language = (tokens.length > 0 ? tokens[0] : "");
       String country = (tokens.length > 1 ? tokens[1] : "");
       validateLocalePart(language);
       validateLocalePart(country);

       String variant = "";
       if (tokens.length > 2) {
           // There is definitely a variant, and it is everything after the country
           // code sans the separator between the country code and the variant.
           int endIndexOfCountryCode = localeString.indexOf(country, language.length()) + country.length();
           // Strip off any leading '_' and whitespace, what's left is the variant.
           variant = trimLeadingWhitespace(localeString.substring(endIndexOfCountryCode));
           if (variant.startsWith("_")) {
               variant = trimLeadingCharacter(variant, '_');
           }
       }

       if (variant.isEmpty() && country.startsWith("#")) {
           variant = country;
           country = "";
       }

       return (language.length() > 0 ? new Locale(language, country, variant) : null);
   }

   private static void validateLocalePart(String localePart) {
       for (int i = 0; i < localePart.length(); i++) {
           char ch = localePart.charAt(i);
           if (ch != ' ' && ch != '_' && ch != '-' && ch != '#' && !Character.isLetterOrDigit(ch)) {
               throw new IllegalArgumentException(
                       "Locale part \"" + localePart + "\" contains invalid characters");
           }
       }
   }

   /**
    * Determine the RFC 3066 compliant language tag,
    * as used for the HTTP "Accept-Language" header.
    * @param locale the Locale to transform to a language tag
    * @return the RFC 3066 compliant language tag as {@code String}
    * @deprecated as of 5.0.4, in favor of {@link Locale#toLanguageTag()}
    */
   @Deprecated
   public static String toLanguageTag(Locale locale) {
       return locale.getLanguage() + (hasText(locale.getCountry()) ? "-" + locale.getCountry() : "");
   }

   /**
    * Parse the given {@code timeZoneString} value into a {@link TimeZone}.
    * @param timeZoneString the time zone {@code String}, following {@link TimeZone#getTimeZone(String)}
    * but throwing {@link IllegalArgumentException} in case of an invalid time zone specification
    * @return a corresponding {@link TimeZone} instance
    * @throws IllegalArgumentException in case of an invalid time zone specification
    */
   public static TimeZone parseTimeZoneString(String timeZoneString) {
       TimeZone timeZone = TimeZone.getTimeZone(timeZoneString);
       if ("GMT".equals(timeZone.getID()) && !timeZoneString.startsWith("GMT")) {
           // We don't want that GMT fallback...
           throw new IllegalArgumentException("Invalid time zone specification '" + timeZoneString + "'");
       }
       return timeZone;
   }


   //---------------------------------------------------------------------
   // Convenience methods for working with String arrays
   //---------------------------------------------------------------------

   /**
    * Copy the given {@link Collection} into a {@code String} array.
    * <p>The {@code Collection} must contain {@code String} elements only.
    * @param collection the {@code Collection} to copy
    * (potentially {@code null} or empty)
    * @return the resulting {@code String} array
    */
   public static String[] toStringArray( Collection<String> collection) {
       return (!CollectionUtils.isEmpty(collection) ? collection.toArray(EMPTY_STRING_ARRAY) : EMPTY_STRING_ARRAY);
   }

   /**
    * Copy the given {@link Enumeration} into a {@code String} array.
    * <p>The {@code Enumeration} must contain {@code String} elements only.
    * @param enumeration the {@code Enumeration} to copy
    * (potentially {@code null} or empty)
    * @return the resulting {@code String} array
    */
   public static String[] toStringArray( Enumeration<String> enumeration) {
       return (enumeration != null ? toStringArray(Collections.list(enumeration)) : EMPTY_STRING_ARRAY);
   }

   /**
    * Append the given {@code String} to the given {@code String} array,
    * returning a new array consisting of the input array contents plus
    * the given {@code String}.
    * @param array the array to append to (can be {@code null})
    * @param str the {@code String} to append
    * @return the new array (never {@code null})
    */
   public static String[] addStringToArray( String[] array, String str) {
       if (PObjectUtils.isEmpty(array)) {
           return new String[] {str};
       }

       String[] newArr = new String[array.length + 1];
       System.arraycopy(array, 0, newArr, 0, array.length);
       newArr[array.length] = str;
       return newArr;
   }

   /**
    * Concatenate the given {@code String} arrays into one,
    * with overlapping array elements included twice.
    * <p>The order of elements in the original arrays is preserved.
    * @param array1 the first array (can be {@code null})
    * @param array2 the second array (can be {@code null})
    * @return the new array ({@code null} if both given arrays were {@code null})
    */

   public static String[] concatenateStringArrays( String[] array1,  String[] array2) {
       if (PObjectUtils.isEmpty(array1)) {
           return array2;
       }
       if (PObjectUtils.isEmpty(array2)) {
           return array1;
       }

       String[] newArr = new String[array1.length + array2.length];
       System.arraycopy(array1, 0, newArr, 0, array1.length);
       System.arraycopy(array2, 0, newArr, array1.length, array2.length);
       return newArr;
   }

   /**
    * Merge the given {@code String} arrays into one, with overlapping
    * array elements only included once.
    * <p>The order of elements in the original arrays is preserved
    * (with the exception of overlapping elements, which are only
    * included on their first occurrence).
    * @param array1 the first array (can be {@code null})
    * @param array2 the second array (can be {@code null})
    * @return the new array ({@code null} if both given arrays were {@code null})
    * @deprecated as of 4.3.15, in favor of manual merging via {@link LinkedHashSet}
    * (with every entry included at most once, even entries within the first array)
    */
   @Deprecated

   public static String[] mergeStringArrays( String[] array1,  String[] array2) {
       if (PObjectUtils.isEmpty(array1)) {
           return array2;
       }
       if (PObjectUtils.isEmpty(array2)) {
           return array1;
       }

       List<String> result = new ArrayList<>(Arrays.asList(array1));
       for (String str : array2) {
           if (!result.contains(str)) {
               result.add(str);
           }
       }
       return toStringArray(result);
   }

   /**
    * Sort the given {@code String} array if necessary.
    * @param array the original array (potentially empty)
    * @return the array in sorted form (never {@code null})
    */
   public static String[] sortStringArray(String[] array) {
       if (PObjectUtils.isEmpty(array)) {
           return array;
       }

       Arrays.sort(array);
       return array;
   }

   /**
    * Trim the elements of the given {@code String} array, calling
    * {@code String.trim()} on each non-null element.
    * @param array the original {@code String} array (potentially empty)
    * @return the resulting array (of the same size) with trimmed elements
    */
   public static String[] trimArrayElements(String[] array) {
       if (PObjectUtils.isEmpty(array)) {
           return array;
       }

       String[] result = new String[array.length];
       for (int i = 0; i < array.length; i++) {
           String element = array[i];
           result[i] = (element != null ? element.trim() : null);
       }
       return result;
   }

   /**
    * Remove duplicate strings from the given array.
    * <p>As of 4.2, it preserves the original order, as it uses a {@link LinkedHashSet}.
    * @param array the {@code String} array (potentially empty)
    * @return an array without duplicates, in natural sort order
    */
   public static String[] removeDuplicateStrings(String[] array) {
       if (PObjectUtils.isEmpty(array)) {
           return array;
       }

       Set<String> set = new LinkedHashSet<>(Arrays.asList(array));
       return toStringArray(set);
   }

   /**
    * Split a {@code String} at the first occurrence of the delimiter.
    * Does not include the delimiter in the result.
    * @param toSplit the string to split (potentially {@code null} or empty)
    * @param delimiter to split the string up with (potentially {@code null} or empty)
    * @return a two element array with index 0 being before the delimiter, and
    * index 1 being after the delimiter (neither element includes the delimiter);
    * or {@code null} if the delimiter wasn't found in the given input {@code String}
    */

   public static String[] split( String toSplit,  String delimiter) {
       if (!hasLength(toSplit) || !hasLength(delimiter)) {
           return null;
       }
       int offset = toSplit.indexOf(delimiter);
       if (offset < 0) {
           return null;
       }

       String beforeDelimiter = toSplit.substring(0, offset);
       String afterDelimiter = toSplit.substring(offset + delimiter.length());
       return new String[] {beforeDelimiter, afterDelimiter};
   }

   /**
    * Take an array of strings and split each element based on the given delimiter.
    * A {@code Properties} instance is then generated, with the left of the delimiter
    * providing the key, and the right of the delimiter providing the value.
    * <p>Will trim both the key and value before adding them to the {@code Properties}.
    * @param array the array to process
    * @param delimiter to split each element using (typically the equals symbol)
    * @return a {@code Properties} instance representing the array contents,
    * or {@code null} if the array to process was {@code null} or empty
    */

   public static Properties splitArrayElementsIntoProperties(String[] array, String delimiter) {
       return splitArrayElementsIntoProperties(array, delimiter, null);
   }

   /**
    * Take an array of strings and split each element based on the given delimiter.
    * A {@code Properties} instance is then generated, with the left of the
    * delimiter providing the key, and the right of the delimiter providing the value.
    * <p>Will trim both the key and value before adding them to the
    * {@code Properties} instance.
    * @param array the array to process
    * @param delimiter to split each element using (typically the equals symbol)
    * @param charsToDelete one or more characters to remove from each element
    * prior to attempting the split operation (typically the quotation mark
    * symbol), or {@code null} if no removal should occur
    * @return a {@code Properties} instance representing the array contents,
    * or {@code null} if the array to process was {@code null} or empty
    */

   public static Properties splitArrayElementsIntoProperties(
           String[] array, String delimiter,  String charsToDelete) {

       if (PObjectUtils.isEmpty(array)) {
           return null;
       }

       Properties result = new Properties();
       for (String element : array) {
           if (charsToDelete != null) {
               element = deleteAny(element, charsToDelete);
           }
           String[] splittedElement = split(element, delimiter);
           if (splittedElement == null) {
               continue;
           }
           result.setProperty(splittedElement[0].trim(), splittedElement[1].trim());
       }
       return result;
   }

   /**
    * Tokenize the given {@code String} into a {@code String} array via a
    * {@link StringTokenizer}.
    * <p>Trims tokens and omits empty tokens.
    * <p>The given {@code delimiters} string can consist of any number of
    * delimiter characters. Each of those characters can be used to separate
    * tokens. A delimiter is always a single character; for multi-character
    * delimiters, consider using {@link #delimitedListToStringArray}.
    * @param str the {@code String} to tokenize (potentially {@code null} or empty)
    * @param delimiters the delimiter characters, assembled as a {@code String}
    * (each of the characters is individually considered as a delimiter)
    * @return an array of the tokens
    * @see StringTokenizer
    * @see String#trim()
    * @see #delimitedListToStringArray
    */
   public static String[] tokenizeToStringArray( String str, String delimiters) {
       return tokenizeToStringArray(str, delimiters, true, true);
   }

   /**
    * Tokenize the given {@code String} into a {@code String} array via a
    * {@link StringTokenizer}.
    * <p>The given {@code delimiters} string can consist of any number of
    * delimiter characters. Each of those characters can be used to separate
    * tokens. A delimiter is always a single character; for multi-character
    * delimiters, consider using {@link #delimitedListToStringArray}.
    * @param str the {@code String} to tokenize (potentially {@code null} or empty)
    * @param delimiters the delimiter characters, assembled as a {@code String}
    * (each of the characters is individually considered as a delimiter)
    * @param trimTokens trim the tokens via {@link String#trim()}
    * @param ignoreEmptyTokens omit empty tokens from the result array
    * (only applies to tokens that are empty after trimming; StringTokenizer
    * will not consider subsequent delimiters as token in the first place).
    * @return an array of the tokens
    * @see StringTokenizer
    * @see String#trim()
    * @see #delimitedListToStringArray
    */
   public static String[] tokenizeToStringArray(
            String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {

       if (str == null) {
           return EMPTY_STRING_ARRAY;
       }

       StringTokenizer st = new StringTokenizer(str, delimiters);
       List<String> tokens = new ArrayList<>();
       while (st.hasMoreTokens()) {
           String token = st.nextToken();
           if (trimTokens) {
               token = token.trim();
           }
           if (!ignoreEmptyTokens || token.length() > 0) {
               tokens.add(token);
           }
       }
       return toStringArray(tokens);
   }

   /**
    * Take a {@code String} that is a delimited list and convert it into a
    * {@code String} array.
    * <p>A single {@code delimiter} may consist of more than one character,
    * but it will still be considered as a single delimiter string, rather
    * than as bunch of potential delimiter characters, in contrast to
    * {@link #tokenizeToStringArray}.
    * @param str the input {@code String} (potentially {@code null} or empty)
    * @param delimiter the delimiter between elements (this is a single delimiter,
    * rather than a bunch individual delimiter characters)
    * @return an array of the tokens in the list
    * @see #tokenizeToStringArray
    */
   public static String[] delimitedListToStringArray( String str,  String delimiter) {
       return delimitedListToStringArray(str, delimiter, null);
   }

   /**
    * Take a {@code String} that is a delimited list and convert it into
    * a {@code String} array.
    * <p>A single {@code delimiter} may consist of more than one character,
    * but it will still be considered as a single delimiter string, rather
    * than as bunch of potential delimiter characters, in contrast to
    * {@link #tokenizeToStringArray}.
    * @param str the input {@code String} (potentially {@code null} or empty)
    * @param delimiter the delimiter between elements (this is a single delimiter,
    * rather than a bunch individual delimiter characters)
    * @param charsToDelete a set of characters to delete; useful for deleting unwanted
    * line breaks: e.g. "\r\n\f" will delete all new lines and line feeds in a {@code String}
    * @return an array of the tokens in the list
    * @see #tokenizeToStringArray
    */
   public static String[] delimitedListToStringArray(
            String str,  String delimiter,  String charsToDelete) {

       if (str == null) {
           return EMPTY_STRING_ARRAY;
       }
       if (delimiter == null) {
           return new String[] {str};
       }

       List<String> result = new ArrayList<>();
       if (delimiter.isEmpty()) {
           for (int i = 0; i < str.length(); i++) {
               result.add(deleteAny(str.substring(i, i + 1), charsToDelete));
           }
       }
       else {
           int pos = 0;
           int delPos;
           while ((delPos = str.indexOf(delimiter, pos)) != -1) {
               result.add(deleteAny(str.substring(pos, delPos), charsToDelete));
               pos = delPos + delimiter.length();
           }
           if (str.length() > 0 && pos <= str.length()) {
               // Add rest of String, but not in case of empty input.
               result.add(deleteAny(str.substring(pos), charsToDelete));
           }
       }
       return toStringArray(result);
   }

   /**
    * Convert a comma delimited list (e.g., a row from a CSV file) into an
    * array of strings.
    * @param str the input {@code String} (potentially {@code null} or empty)
    * @return an array of strings, or the empty array in case of empty input
    */
   public static String[] commaDelimitedListToStringArray( String str) {
       return delimitedListToStringArray(str, ",");
   }

   /**
    * Convert a comma delimited list (e.g., a row from a CSV file) into a set.
    * <p>Note that this will suppress duplicates, and as of 4.2, the elements in
    * the returned set will preserve the original order in a {@link LinkedHashSet}.
    * @param str the input {@code String} (potentially {@code null} or empty)
    * @return a set of {@code String} entries in the list
    * @see #removeDuplicateStrings(String[])
    */
   public static Set<String> commaDelimitedListToSet( String str) {
       String[] tokens = commaDelimitedListToStringArray(str);
       return new LinkedHashSet<>(Arrays.asList(tokens));
   }

   /**
    * Convert a {@link Collection} to a delimited {@code String} (e.g. CSV).
    * <p>Useful for {@code toString()} implementations.
    * @param coll the {@code Collection} to convert (potentially {@code null} or empty)
    * @param delim the delimiter to use (typically a ",")
    * @param prefix the {@code String} to start each element with
    * @param suffix the {@code String} to end each element with
    * @return the delimited {@code String}
    */
   public static String collectionToDelimitedString(
            Collection<?> coll, String delim, String prefix, String suffix) {

       if (CollectionUtils.isEmpty(coll)) {
           return "";
       }

       StringBuilder sb = new StringBuilder();
       Iterator<?> it = coll.iterator();
       while (it.hasNext()) {
           sb.append(prefix).append(it.next()).append(suffix);
           if (it.hasNext()) {
               sb.append(delim);
           }
       }
       return sb.toString();
   }

   /**
    * Convert a {@code Collection} into a delimited {@code String} (e.g. CSV).
    * <p>Useful for {@code toString()} implementations.
    * @param coll the {@code Collection} to convert (potentially {@code null} or empty)
    * @param delim the delimiter to use (typically a ",")
    * @return the delimited {@code String}
    */
   public static String collectionToDelimitedString( Collection<?> coll, String delim) {
       return collectionToDelimitedString(coll, delim, "", "");
   }

   /**
    * Convert a {@code Collection} into a delimited {@code String} (e.g., CSV).
    * <p>Useful for {@code toString()} implementations.
    * @param coll the {@code Collection} to convert (potentially {@code null} or empty)
    * @return the delimited {@code String}
    */
   public static String collectionToCommaDelimitedString( Collection<?> coll) {
       return collectionToDelimitedString(coll, ",");
   }

   /**
    * Convert a {@code String} array into a delimited {@code String} (e.g. CSV).
    * <p>Useful for {@code toString()} implementations.
    * @param arr the array to display (potentially {@code null} or empty)
    * @param delim the delimiter to use (typically a ",")
    * @return the delimited {@code String}
    */
   public static String arrayToDelimitedString( Object[] arr, String delim) {
       if (PObjectUtils.isEmpty(arr)) {
           return "";
       }
       if (arr.length == 1) {
           return PObjectUtils.nullSafeToString(arr[0]);
       }

       StringJoiner sj = new StringJoiner(delim);
       for (Object o : arr) {
           sj.add(String.valueOf(o));
       }
       return sj.toString();
   }

   /**
    * Convert a {@code String} array into a comma delimited {@code String}
    * (i.e., CSV).
    * <p>Useful for {@code toString()} implementations.
    * @param arr the array to display (potentially {@code null} or empty)
    * @return the delimited {@code String}
    */
   public static String arrayToCommaDelimitedString( Object[] arr) {
       return arrayToDelimitedString(arr, ",");
   }

}
